1. Field of the Invention
The present invention relates to the storage of goods above a processing device using an overhead traveling vehicle, a shuttle carriage, and a buffer.
2. Description of the Related Art
A system for using an overhead traveling vehicle to transport a large number of goods to and from a processing device is used in clean rooms and the like. JP4296601 proposes a system in which a local carriage is arranged above a load port in the front surface of a processing device, and a buffer is arranged between the track for the local carriage and the track for an overhead traveling vehicle. With this system, the overhead traveling vehicle is used exclusively for transport to the buffer, and transport between the buffer and the load port of the processing device is performed by the local carriage.
JP2012-114406 discloses a system in which a track for an overhead traveling vehicle and a track for a local carriage are arranged one above the other above a load port, and a buffer used in common by the overhead traveling vehicle and the local carriage is provided above the load port. With this system, both the overhead traveling vehicle and the local carriage can transport goods to and from the load port, and use the buffer in common.
In both of the systems in JP4296601 and JP2012-114406, the buffer is arranged in the ceiling space above the passageway in front of the processing device. There is a limit on the number of buffers that can be installed since the buffer installation space is limited to the space in the passageway. Furthermore, although the ceiling space is used, arranging the buffers in the passageway limits the use of the passageway.